<feed xmlns='http://www.w3.org/2005/Atom'>
<title>u-boot.git/arch/mips/config.mk, branch master</title>
<subtitle>Unnamed repository; edit this file 'description' to name the repository.
</subtitle>
<link rel='alternate' type='text/html' href='http://cgit.235523.xyz/u-boot.git/'/>
<entry>
<title>arch: Use CONFIG_XPL_BUILD instead of CONFIG_SPL_BUILD</title>
<updated>2024-10-11T17:44:47+00:00</updated>
<author>
<name>Simon Glass</name>
<email>sjg@chromium.org</email>
</author>
<published>2024-09-30T01:49:46+00:00</published>
<link rel='alternate' type='text/html' href='http://cgit.235523.xyz/u-boot.git/commit/?id=bef9fdbed2e525ce9264d2ae2fbcb37db7472052'/>
<id>bef9fdbed2e525ce9264d2ae2fbcb37db7472052</id>
<content type='text'>
Use the new symbol to refer to any 'SPL' build, including TPL and VPL

Signed-off-by: Simon Glass &lt;sjg@chromium.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use the new symbol to refer to any 'SPL' build, including TPL and VPL

Signed-off-by: Simon Glass &lt;sjg@chromium.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Convert CONFIG_STANDALONE_LOAD_ADDR to Kconfig</title>
<updated>2022-12-22T15:31:48+00:00</updated>
<author>
<name>Tom Rini</name>
<email>trini@konsulko.com</email>
</author>
<published>2022-12-02T21:42:44+00:00</published>
<link rel='alternate' type='text/html' href='http://cgit.235523.xyz/u-boot.git/commit/?id=32b7e39db4d3af0d94f1387a7641152f375b23ac'/>
<id>32b7e39db4d3af0d94f1387a7641152f375b23ac</id>
<content type='text'>
This converts the following to Kconfig:
   CONFIG_STANDALONE_LOAD_ADDR

Signed-off-by: Tom Rini &lt;trini@konsulko.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This converts the following to Kconfig:
   CONFIG_STANDALONE_LOAD_ADDR

Signed-off-by: Tom Rini &lt;trini@konsulko.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>linker_lists: Rename sections to remove . prefix</title>
<updated>2022-06-23T16:58:18+00:00</updated>
<author>
<name>Andrew Scull</name>
<email>ascull@google.com</email>
</author>
<published>2022-05-30T10:00:04+00:00</published>
<link rel='alternate' type='text/html' href='http://cgit.235523.xyz/u-boot.git/commit/?id=99e2fbcb69f0759432c4cfa0b6e1afa006f22930'/>
<id>99e2fbcb69f0759432c4cfa0b6e1afa006f22930</id>
<content type='text'>
Rename the sections used to implement linker lists so they begin with
'__u_boot_list' rather than '.u_boot_list'. The double underscore at the
start is still distinct from the single underscore used by the symbol
names.

Having a '.' in the section names conflicts with clang's ASAN
instrumentation which tries to add redzones between the linker list
elements, causing expected accesses to fail. However, clang doesn't try
to add redzones to user sections, which are names with all alphanumeric
and underscore characters.

Signed-off-by: Andrew Scull &lt;ascull@google.com&gt;
Reviewed-by: Simon Glass &lt;sjg@chromium.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Rename the sections used to implement linker lists so they begin with
'__u_boot_list' rather than '.u_boot_list'. The double underscore at the
start is still distinct from the single underscore used by the symbol
names.

Having a '.' in the section names conflicts with clang's ASAN
instrumentation which tries to add redzones between the linker list
elements, causing expected accesses to fail. However, clang doesn't try
to add redzones to user sections, which are names with all alphanumeric
and underscore characters.

Signed-off-by: Andrew Scull &lt;ascull@google.com&gt;
Reviewed-by: Simon Glass &lt;sjg@chromium.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kconfig / kbuild: Re-sync with Linux 4.19</title>
<updated>2020-04-10T15:18:32+00:00</updated>
<author>
<name>Tom Rini</name>
<email>trini@konsulko.com</email>
</author>
<published>2020-03-27T15:46:27+00:00</published>
<link rel='alternate' type='text/html' href='http://cgit.235523.xyz/u-boot.git/commit/?id=587e4a4296982f85b2a40fc8a704db65079e0aac'/>
<id>587e4a4296982f85b2a40fc8a704db65079e0aac</id>
<content type='text'>
Align Kconfig and Kbuild logic to Linux 4.19 release with minimal impact
on files outside of this scope.

Our previous Kconfig sync was done by commit 5972ff077e0f ("kconfig /
kbuild: re-sync with Linux 4.18").

In this particular re-sync in order to keep clang support working a
number of related changes needed to be pulled in that had been missed
previously.  Not all of these changes we easily traceable and so have
been omitted from the list below.

The imported Linux commits are:
[From prior to v4.18]
9f3f1fd29976 kbuild: Add __cc-option macro
d7f14c66c273 kbuild: Enable Large File Support for hostprogs
6d79a7b424a5 kbuild: suppress warnings from 'getconf LFS_*'
24403874316a Shared library support
86a9df597cdd kbuild: fix linker feature test macros when cross compiling with Clang
0294e6f4a000 kbuild: simplify ld-option implementation

[From v4.18 to v4.19]
96f14fe738b6 kbuild: Rename HOSTCFLAGS to KBUILD_HOSTCFLAGS
10844aebf448 kbuild: Rename HOSTCXXFLAGS to KBUILD_HOSTCXXFLAGS
b90a368000ab kbuild: Rename HOSTLDFLAGS to KBUILD_HOSTLDFLAGS
8377bd2b9ee1 kbuild: Rename HOST_LOADLIBES to KBUILD_HOSTLDLIBS
f92d19e0ef9b kbuild: Use HOST*FLAGS options from the command line
4ab3b80159d4 kconfig: check for pkg-config on make {menu,n,g,x}config
693359f7ac90 kconfig: rename SYMBOL_AUTO to SYMBOL_NO_WRITE
f60b992e30ff kbuild: replace $(LDFLAGS) $(ldflags-y) with $(ld_flags)
2fb9279f2c3e kbuild: change ld_flags to contain LDFLAGS_$(@F)
c931d34ea085 arm64: build with baremetal linker target instead of Linux when available
5accd7f3360e kconfig: handle format string before calling conf_message_callback()
a2ff4040151a kconfig: rename file_write_dep and move it to confdata.c
0608182ad542 kconfig: split out useful helpers in confdata.c
adc18acf42a1 kconfig: remove unneeded directory generation from local*config
79123b1389cc kconfig: create directories needed for syncconfig by itself
16952b77d8b5 kconfig: make syncconfig update .config regardless of sym_change_count
d6c6ab93e17f kbuild: remove deprecated host-progs variable
56869d45e364 kconfig: fix the rule of mainmenu_stmt symbol
c151272d1687 kconfig: remove unused sym_get_env_prop() function
1880861226c1 kconfig: remove P_ENV property type
e3fd9b5384f3 scripts/dtc: consolidate include path options in Makefile
4bf6a9af0e91 kconfig: add build-only configurator targets
f1575595d156 kconfig: error out when seeing recursive dependency
5e8c5299d315 kconfig: report recursive dependency involving 'imply'
f498926c47aa kconfig: improve the recursive dependency report
98a4afbfafd2 kconfig: fix "Can't open ..." in parallel build
9a9ddcf47831 kconfig: suppress "configuration written to .config" for syncconfig
87a32e624037 kbuild: pass LDFLAGS to recordmcount.pl
d503ac531a52 kbuild: rename LDFLAGS to KBUILD_LDFLAGS
217c3e019675 disable stringop truncation warnings for now
bc8d2e20a3eb kconfig: remove a spurious self-assignment
fd65465b7016 kconfig: do not require pkg-config on make {menu,n}config
5a4630aadb9a ftrace: Build with CPPFLAGS to get -Qunused-arguments

Note that this adds new cleanup work to do in that we should adapt the
shared library support we have to what is now upstream.

Signed-off-by: Tom Rini &lt;trini@konsulko.com&gt;
Reviewed-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Align Kconfig and Kbuild logic to Linux 4.19 release with minimal impact
on files outside of this scope.

Our previous Kconfig sync was done by commit 5972ff077e0f ("kconfig /
kbuild: re-sync with Linux 4.18").

In this particular re-sync in order to keep clang support working a
number of related changes needed to be pulled in that had been missed
previously.  Not all of these changes we easily traceable and so have
been omitted from the list below.

The imported Linux commits are:
[From prior to v4.18]
9f3f1fd29976 kbuild: Add __cc-option macro
d7f14c66c273 kbuild: Enable Large File Support for hostprogs
6d79a7b424a5 kbuild: suppress warnings from 'getconf LFS_*'
24403874316a Shared library support
86a9df597cdd kbuild: fix linker feature test macros when cross compiling with Clang
0294e6f4a000 kbuild: simplify ld-option implementation

[From v4.18 to v4.19]
96f14fe738b6 kbuild: Rename HOSTCFLAGS to KBUILD_HOSTCFLAGS
10844aebf448 kbuild: Rename HOSTCXXFLAGS to KBUILD_HOSTCXXFLAGS
b90a368000ab kbuild: Rename HOSTLDFLAGS to KBUILD_HOSTLDFLAGS
8377bd2b9ee1 kbuild: Rename HOST_LOADLIBES to KBUILD_HOSTLDLIBS
f92d19e0ef9b kbuild: Use HOST*FLAGS options from the command line
4ab3b80159d4 kconfig: check for pkg-config on make {menu,n,g,x}config
693359f7ac90 kconfig: rename SYMBOL_AUTO to SYMBOL_NO_WRITE
f60b992e30ff kbuild: replace $(LDFLAGS) $(ldflags-y) with $(ld_flags)
2fb9279f2c3e kbuild: change ld_flags to contain LDFLAGS_$(@F)
c931d34ea085 arm64: build with baremetal linker target instead of Linux when available
5accd7f3360e kconfig: handle format string before calling conf_message_callback()
a2ff4040151a kconfig: rename file_write_dep and move it to confdata.c
0608182ad542 kconfig: split out useful helpers in confdata.c
adc18acf42a1 kconfig: remove unneeded directory generation from local*config
79123b1389cc kconfig: create directories needed for syncconfig by itself
16952b77d8b5 kconfig: make syncconfig update .config regardless of sym_change_count
d6c6ab93e17f kbuild: remove deprecated host-progs variable
56869d45e364 kconfig: fix the rule of mainmenu_stmt symbol
c151272d1687 kconfig: remove unused sym_get_env_prop() function
1880861226c1 kconfig: remove P_ENV property type
e3fd9b5384f3 scripts/dtc: consolidate include path options in Makefile
4bf6a9af0e91 kconfig: add build-only configurator targets
f1575595d156 kconfig: error out when seeing recursive dependency
5e8c5299d315 kconfig: report recursive dependency involving 'imply'
f498926c47aa kconfig: improve the recursive dependency report
98a4afbfafd2 kconfig: fix "Can't open ..." in parallel build
9a9ddcf47831 kconfig: suppress "configuration written to .config" for syncconfig
87a32e624037 kbuild: pass LDFLAGS to recordmcount.pl
d503ac531a52 kbuild: rename LDFLAGS to KBUILD_LDFLAGS
217c3e019675 disable stringop truncation warnings for now
bc8d2e20a3eb kconfig: remove a spurious self-assignment
fd65465b7016 kconfig: do not require pkg-config on make {menu,n}config
5a4630aadb9a ftrace: Build with CPPFLAGS to get -Qunused-arguments

Note that this adds new cleanup work to do in that we should adapt the
shared library support we have to what is now upstream.

Signed-off-by: Tom Rini &lt;trini@konsulko.com&gt;
Reviewed-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arch: Add explicit linker script for u-boot-elf</title>
<updated>2020-04-03T15:52:55+00:00</updated>
<author>
<name>Michal Simek</name>
<email>michal.simek@xilinx.com</email>
</author>
<published>2020-03-30T11:58:59+00:00</published>
<link rel='alternate' type='text/html' href='http://cgit.235523.xyz/u-boot.git/commit/?id=e14ba8a57703457e31248eccd4959cead92e2063'/>
<id>e14ba8a57703457e31248eccd4959cead92e2063</id>
<content type='text'>
Commit f4dc714aaa2d ("arm64: Turn u-boot.bin back into an ELF file after
relocate-rela")
introduce REMAKE_ELF option to recreate u-boot.elf from u-boot -&gt;
u-boot.bin + DT -&gt; u-boot.elf.

The best is to ilustrate it from make V=1 output
  cat u-boot-nodtb.bin dts/dt.dtb &gt; u-boot-dtb.bin
  cp u-boot-dtb.bin u-boot.bin
aarch64-linux-gnu-objcopy -I binary -B aarch64 -O elf64-littleaarch64  u-boot.bin u-boot-elf.o
  aarch64-linux-gnu-ld.bfd u-boot-elf.o -o u-boot.elf --defsym="_start"=0x8000000 -Ttext=0x8000000

Last command has no explicit linker script passed that's why toolchain
internal linker script is used.
In Binutils 2.32 case it contains SIZEOF_HEADERS symbol which has changed
behavior by commit
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=64029e93683a266c38d19789e780f3748bd6a188
which result in situation that program headers has changed from
(xilinx_zynqmp_mini_defconfig)

Program Headers:
  Type           Offset             VirtAddr           PhysAddr
                 FileSiz            MemSiz              Flags  Align
  LOAD           0x0000000000010000 0x00000000fffc0000 0x00000000fffc0000
                 0x0000000000018918 0x0000000000018918  RW     0x10000

to

Program Headers:
  Type           Offset             VirtAddr           PhysAddr
                 FileSiz            MemSiz              Flags  Align
  LOAD           0x0000000000000000 0x00000000fffb0000 0x00000000fffb0000
                 0x0000000000028918 0x0000000000028918  RW     0x10000

Xilinx tools like XSDB or Bootgen are using program headers for loading ELF
to the right location and by above binutils change ELF is loaded to
incorrect location.

The patch is explicitly use u-boot-elf.lds (just cat now) for u-boot.elf
recreation which is called when REMAKE_ELF is setup.
By purpose u-boot-elf.lds doesn't contain OUTPUT_FORMAT/OUTPUT_ARCH to be
able to use by all archs.

Signed-off-by: Michal Simek &lt;michal.simek@xilinx.com&gt;
Reviewed-by: Tom Rini &lt;trini@konsulko.com&gt;
Reviewed-by: Daniel Schwierzeck &lt;daniel.schwierzeck@gmail.com&gt;
Tested-By: Álvaro Fernández Rojas &lt;noltari@gmail.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit f4dc714aaa2d ("arm64: Turn u-boot.bin back into an ELF file after
relocate-rela")
introduce REMAKE_ELF option to recreate u-boot.elf from u-boot -&gt;
u-boot.bin + DT -&gt; u-boot.elf.

The best is to ilustrate it from make V=1 output
  cat u-boot-nodtb.bin dts/dt.dtb &gt; u-boot-dtb.bin
  cp u-boot-dtb.bin u-boot.bin
aarch64-linux-gnu-objcopy -I binary -B aarch64 -O elf64-littleaarch64  u-boot.bin u-boot-elf.o
  aarch64-linux-gnu-ld.bfd u-boot-elf.o -o u-boot.elf --defsym="_start"=0x8000000 -Ttext=0x8000000

Last command has no explicit linker script passed that's why toolchain
internal linker script is used.
In Binutils 2.32 case it contains SIZEOF_HEADERS symbol which has changed
behavior by commit
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=64029e93683a266c38d19789e780f3748bd6a188
which result in situation that program headers has changed from
(xilinx_zynqmp_mini_defconfig)

Program Headers:
  Type           Offset             VirtAddr           PhysAddr
                 FileSiz            MemSiz              Flags  Align
  LOAD           0x0000000000010000 0x00000000fffc0000 0x00000000fffc0000
                 0x0000000000018918 0x0000000000018918  RW     0x10000

to

Program Headers:
  Type           Offset             VirtAddr           PhysAddr
                 FileSiz            MemSiz              Flags  Align
  LOAD           0x0000000000000000 0x00000000fffb0000 0x00000000fffb0000
                 0x0000000000028918 0x0000000000028918  RW     0x10000

Xilinx tools like XSDB or Bootgen are using program headers for loading ELF
to the right location and by above binutils change ELF is loaded to
incorrect location.

The patch is explicitly use u-boot-elf.lds (just cat now) for u-boot.elf
recreation which is called when REMAKE_ELF is setup.
By purpose u-boot-elf.lds doesn't contain OUTPUT_FORMAT/OUTPUT_ARCH to be
able to use by all archs.

Signed-off-by: Michal Simek &lt;michal.simek@xilinx.com&gt;
Reviewed-by: Tom Rini &lt;trini@konsulko.com&gt;
Reviewed-by: Daniel Schwierzeck &lt;daniel.schwierzeck@gmail.com&gt;
Tested-By: Álvaro Fernández Rojas &lt;noltari@gmail.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: fix linking of standalone programs</title>
<updated>2018-11-18T15:02:23+00:00</updated>
<author>
<name>Daniel Schwierzeck</name>
<email>daniel.schwierzeck@gmail.com</email>
</author>
<published>2018-09-23T17:15:17+00:00</published>
<link rel='alternate' type='text/html' href='http://cgit.235523.xyz/u-boot.git/commit/?id=1bef0c530beaaba08b8ca7a9ec6ce6dc25f62dfb'/>
<id>1bef0c530beaaba08b8ca7a9ec6ce6dc25f62dfb</id>
<content type='text'>
Use the global MIPS specific u-boot.lds for linking standalone programs
instead of the outdated ones in examples/standalone/. Also pass --gc-sections
in LDFLAGS_STANDALONE to optimize the size of standalone programs.
Finally remove the deprecated config.mk files in arch/mips/cpu/mips[32,64]/.

Signed-off-by: Daniel Schwierzeck &lt;daniel.schwierzeck@gmail.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use the global MIPS specific u-boot.lds for linking standalone programs
instead of the outdated ones in examples/standalone/. Also pass --gc-sections
in LDFLAGS_STANDALONE to optimize the size of standalone programs.
Finally remove the deprecated config.mk files in arch/mips/cpu/mips[32,64]/.

Signed-off-by: Daniel Schwierzeck &lt;daniel.schwierzeck@gmail.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: make size of relocation table fixed but configurable</title>
<updated>2018-11-02T21:39:07+00:00</updated>
<author>
<name>Daniel Schwierzeck</name>
<email>daniel.schwierzeck@gmail.com</email>
</author>
<published>2018-11-01T01:02:21+00:00</published>
<link rel='alternate' type='text/html' href='http://cgit.235523.xyz/u-boot.git/commit/?id=963014641117291c15df2425caf46c7b4b979f18'/>
<id>963014641117291c15df2425caf46c7b4b979f18</id>
<content type='text'>
Currently the size of the relocation table will be shrunk
to the actual size needed. Although this gives a maximal
space saving, it messes up the _end symbol. This breaks
features like appended DTBs because the _end symbol doesn't
point to the real end of the U-Boot binary.

Remove the size shrinking and make the size of the relocation
table fixed but configurable. This follows the Linux approach
and the user can adjust the size to his needs.

Also rename the relocation table section from .rel to .data.reloc
to follow the Linux approach and to avoid ambiguities with the
.rel.* sections added by the linker.

Reported-by: Lars Povlsen &lt;lars.povlsen@microsemi.com&gt;
Signed-off-by: Daniel Schwierzeck &lt;daniel.schwierzeck@gmail.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently the size of the relocation table will be shrunk
to the actual size needed. Although this gives a maximal
space saving, it messes up the _end symbol. This breaks
features like appended DTBs because the _end symbol doesn't
point to the real end of the U-Boot binary.

Remove the size shrinking and make the size of the relocation
table fixed but configurable. This follows the Linux approach
and the user can adjust the size to his needs.

Also rename the relocation table section from .rel to .data.reloc
to follow the Linux approach and to avoid ambiguities with the
.rel.* sections added by the linker.

Reported-by: Lars Povlsen &lt;lars.povlsen@microsemi.com&gt;
Signed-off-by: Daniel Schwierzeck &lt;daniel.schwierzeck@gmail.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>SPDX: Convert all of our single license tags to Linux Kernel style</title>
<updated>2018-05-07T13:34:12+00:00</updated>
<author>
<name>Tom Rini</name>
<email>trini@konsulko.com</email>
</author>
<published>2018-05-06T21:58:06+00:00</published>
<link rel='alternate' type='text/html' href='http://cgit.235523.xyz/u-boot.git/commit/?id=83d290c56fab2d38cd1ab4c4cc7099559c1d5046'/>
<id>83d290c56fab2d38cd1ab4c4cc7099559c1d5046</id>
<content type='text'>
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini &lt;trini@konsulko.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini &lt;trini@konsulko.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Stop building position independent code</title>
<updated>2017-07-25T18:44:00+00:00</updated>
<author>
<name>Paul Burton</name>
<email>paul.burton@imgtec.com</email>
</author>
<published>2017-06-19T18:53:47+00:00</published>
<link rel='alternate' type='text/html' href='http://cgit.235523.xyz/u-boot.git/commit/?id=703ec9ddf965063cd79910df281657b056879368'/>
<id>703ec9ddf965063cd79910df281657b056879368</id>
<content type='text'>
U-Boot has up until now built with -fpic for the MIPS architecture,
producing position independent code which uses indirection through a
global offset table, making relocation fairly straightforward as it
simply involves patching up GOT entries.

Using -fpic does however have some downsides. The biggest of these is
that generated code is bloated in various ways. For example, function
calls are indirected through the GOT &amp; the t9 register:

  8f998064   lw     t9,-32668(gp)
  0320f809   jalr   t9

Without -fpic the call is simply:

  0f803f01   jal    be00fc04 &lt;puts&gt;

This is more compact &amp; faster (due to the lack of the load &amp; the
dependency the jump has on its result). It is also easier to read &amp;
debug because the disassembly shows what function is being called,
rather than just an offset from gp which would then have to be looked up
in the ELF to discover the target function.

Another disadvantage of -fpic is that each function begins with a
sequence to calculate the value of the gp register, for example:

  3c1c0004   lui    gp,0x4
  279c3384   addiu  gp,gp,13188
  0399e021   addu   gp,gp,t9

Without using -fpic this sequence no longer appears at the start of each
function, reducing code size considerably.

This patch switches U-Boot from building with -fpic to building with
-fno-pic, in order to gain the benefits described above. The cost of
this is an extra step during the build process to extract relocation
data from the ELF &amp; write it into a new .rel section in a compact
format, plus the added complexity of dealing with multiple types of
relocation rather than the single type that applied to the GOT. The
benefit is smaller, cleaner, more debuggable code. The relocate_code()
function is reimplemented in C to handle the new relocation scheme,
which also makes it easier to read &amp; debug.

Taking maltael_defconfig as an example the size of u-boot.bin built
using the Codescape MIPS 2016.05-06 toolchain (gcc 4.9.2, binutils
2.24.90) shrinks from 254KiB to 224KiB.

Signed-off-by: Paul Burton &lt;paul.burton@imgtec.com&gt;
Cc: Daniel Schwierzeck &lt;daniel.schwierzeck@gmail.com&gt;
Cc: u-boot@lists.denx.de
Reviewed-by: Daniel Schwierzeck &lt;daniel.schwierzeck@gmail.com&gt;
Tested-by: Daniel Schwierzeck &lt;daniel.schwierzeck@gmail.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
U-Boot has up until now built with -fpic for the MIPS architecture,
producing position independent code which uses indirection through a
global offset table, making relocation fairly straightforward as it
simply involves patching up GOT entries.

Using -fpic does however have some downsides. The biggest of these is
that generated code is bloated in various ways. For example, function
calls are indirected through the GOT &amp; the t9 register:

  8f998064   lw     t9,-32668(gp)
  0320f809   jalr   t9

Without -fpic the call is simply:

  0f803f01   jal    be00fc04 &lt;puts&gt;

This is more compact &amp; faster (due to the lack of the load &amp; the
dependency the jump has on its result). It is also easier to read &amp;
debug because the disassembly shows what function is being called,
rather than just an offset from gp which would then have to be looked up
in the ELF to discover the target function.

Another disadvantage of -fpic is that each function begins with a
sequence to calculate the value of the gp register, for example:

  3c1c0004   lui    gp,0x4
  279c3384   addiu  gp,gp,13188
  0399e021   addu   gp,gp,t9

Without using -fpic this sequence no longer appears at the start of each
function, reducing code size considerably.

This patch switches U-Boot from building with -fpic to building with
-fno-pic, in order to gain the benefits described above. The cost of
this is an extra step during the build process to extract relocation
data from the ELF &amp; write it into a new .rel section in a compact
format, plus the added complexity of dealing with multiple types of
relocation rather than the single type that applied to the GOT. The
benefit is smaller, cleaner, more debuggable code. The relocate_code()
function is reimplemented in C to handle the new relocation scheme,
which also makes it easier to read &amp; debug.

Taking maltael_defconfig as an example the size of u-boot.bin built
using the Codescape MIPS 2016.05-06 toolchain (gcc 4.9.2, binutils
2.24.90) shrinks from 254KiB to 224KiB.

Signed-off-by: Paul Burton &lt;paul.burton@imgtec.com&gt;
Cc: Daniel Schwierzeck &lt;daniel.schwierzeck@gmail.com&gt;
Cc: u-boot@lists.denx.de
Reviewed-by: Daniel Schwierzeck &lt;daniel.schwierzeck@gmail.com&gt;
Tested-by: Daniel Schwierzeck &lt;daniel.schwierzeck@gmail.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: add support for generating u-boot.elf</title>
<updated>2017-05-10T14:16:09+00:00</updated>
<author>
<name>Álvaro Fernández Rojas</name>
<email>noltari@gmail.com</email>
</author>
<published>2017-04-20T18:36:27+00:00</published>
<link rel='alternate' type='text/html' href='http://cgit.235523.xyz/u-boot.git/commit/?id=47cf465c25d4c121d4b2befc67aabfa044a52389'/>
<id>47cf465c25d4c121d4b2befc67aabfa044a52389</id>
<content type='text'>
Define PLATFORM_ELFFLAGS for MIPS in order to be able to generate u-boot.elf

Signed-off-by: Álvaro Fernández Rojas &lt;noltari@gmail.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Define PLATFORM_ELFFLAGS for MIPS in order to be able to generate u-boot.elf

Signed-off-by: Álvaro Fernández Rojas &lt;noltari@gmail.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
